Who was the mystery woman?

The film never discloses who she is. Given the status of his marriage, where he and his wife barely speak to each and even sleep apart, I am assuming this mystery woman provided him with companionship. In the scene where the two of them are first spotted by the son, it is the only time in the entire film that the father actually smiles. It appears that they may have met at the National Library. The film doesn't provide enough information to determine if there is a sexual affair going on in the background, but it doesn't really matter. He is an unhappy person with his work and his family life, finding an ounce of happiness on a park bench with an outsider. In a sense, the mystery woman is like another "footnote" in his life.

I took it that the woman in the park, who was also at the ceremony at the end, was the reporter that the award news was "leaked" to by the father to further his notoriety.


"the only way through it is through it " -Jackson Browne

I think she was one of his colleagues. Wasn't she among the group having drinks to celebrate when the son came in upon them? It seemed that showed that any romantic connection was just an imagined suspicion. One of the themes of the movie was the son seeking to find imperfections in his overbearing father, and something like this would have supported that effort - but it was unfounded.

She may be a woman in an extra-marital affair with the father --- an affair (or previous affairs)--- giving rise to Grossman's remark, in the meeting of the academicians, to the son about "things" he (Grossman) knows about the father that the son would be shocked to know.

I didn't think of the mystery woman as someone Eliezer had an affair with. At a later point in the movie she's seen as part of a small group of aging academics celebrating with Eliezer in the library, and this led me to think that the reason he lights up around her (and also around the others) is that she's old-school like him. She and those other handful of scholars see things his way... meticulously reviewing texts in a library. They're "his people" not like the hotshot academics presiding over academic departments.

I'm not saying this 100% rules out that he may have once had an affair... but in truth, I don't see him as the type. The son jumping to that conclusion might say more about what the son wants to see rather than what actually is.

I noticed a few things: First, while Grossman supplies believable reasons for his attitude, Uriel's charge that there's some sort of personal grudge between the two is never really refuted. Second, Grossman says something like "I could say things a son should never have to hear" ...but never actually says any such thing. Third, the conversation in bed between Uriel and his wife about infidelity explicitly delivered to us the idea that Eliezer was capable of (in fact likely to have) an affair. And fourth, Grossman seems to be the only character that's not married.

From all that, my theories are that Grossman and Eliezer competed for the same lady and Eliezer won in a way Grossman didn't like (likely taking away Grossman's "wife"), and that Eliezer had some sort of affair many years in the past which Grossman was somehow aware of.

I never formed any theory about whether the mystery lady is the "same" lady, or just a "similar" lady (it doesn't seem to really matter anyway). I also never formed any theory about whether the "competition" and the "affair" were two separate events, or just two aspects of a single event (and again it doesn't seem to really matter anyway).

Most of the comments on this question seem to miss the point: This relationship of the father's is an instance of how the father has chosen to bend his unflinching commitment to "the truth". It's an act of deception vis-a`-vis his wife and his son. And her presence at the final ceremony suggests that, even though he knows the truth about the award (he has used his philological skills to good end in his investigation of the word "fortress"), the father will continue with the deception and accept the very prize he had come to disdain and loath.